U.S. patent number 10,179,871 [Application Number 15/279,504] was granted by the patent office on 2019-01-15 for two-component binder system with cyclocarbonate and epoxy groups.
This patent grant is currently assigned to Henkel AG & Co. KGaA. The grantee listed for this patent is Henkel AG & Co. KGaA. Invention is credited to Therese Hemery, Hans-Georg Kinzelmann, Olaf Lammerschop.
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United States Patent |
10,179,871 |
Lammerschop , et
al. |
January 15, 2019 |
Two-component binder system with cyclocarbonate and epoxy
groups
Abstract
The present invention relates to a binder system containing a
resin component and a curing agent component, wherein the resin
comprises at least one compound carrying at least two cyclic
carbonate groups and at least one compound carrying at least two
epoxy groups, and the curing agent comprises at least one
multifunctional amine as well as the use of the binder system as an
adhesive/sealant and the use of this adhesive/sealant.
Inventors: |
Lammerschop; Olaf (Krefeld,
DE), Kinzelmann; Hans-Georg (Pulheim, DE),
Hemery; Therese (Duesseldorf, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Henkel AG & Co. KGaA |
Duesseldorf |
N/A |
DE |
|
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Assignee: |
Henkel AG & Co. KGaA
(Duesseldorf, DE)
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Family
ID: |
52998105 |
Appl.
No.: |
15/279,504 |
Filed: |
September 29, 2016 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20170015883 A1 |
Jan 19, 2017 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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PCT/EP2015/057367 |
Apr 2, 2015 |
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Foreign Application Priority Data
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Apr 4, 2014 [DE] |
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10 2014 206 574 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08G
71/04 (20130101); B32B 7/12 (20130101); C08G
71/00 (20130101); C08L 75/12 (20130101); B65D
65/40 (20130101); C07D 317/36 (20130101); C08J
7/0427 (20200101); C09J 175/04 (20130101); B32B
2439/70 (20130101); C08J 2375/04 (20130101) |
Current International
Class: |
C08L
75/12 (20060101); C09J 175/04 (20060101); B32B
7/12 (20060101); C08J 7/04 (20060101); B65D
65/40 (20060101); C08G 71/04 (20060101); C08G
71/00 (20060101); C07D 317/36 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
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|
|
|
2012219869 |
|
Sep 2013 |
|
AU |
|
102558491 |
|
Jul 2012 |
|
CN |
|
3529263 |
|
Feb 1987 |
|
DE |
|
3600602 |
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Jul 1987 |
|
DE |
|
4109649 |
|
Sep 1992 |
|
DE |
|
102004035542 |
|
Feb 2006 |
|
DE |
|
0303158 |
|
Feb 1989 |
|
EP |
|
0328150 |
|
Aug 1989 |
|
EP |
|
1020457 |
|
Jul 2000 |
|
EP |
|
H07224131 |
|
Aug 1995 |
|
JP |
|
2100377 |
|
Dec 1997 |
|
RU |
|
8403701 |
|
Sep 1984 |
|
WO |
|
9429422 |
|
Dec 1994 |
|
WO |
|
9850345 |
|
Nov 1998 |
|
WO |
|
2012113618 |
|
Aug 2012 |
|
WO |
|
WO 2014/158705 |
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Oct 2014 |
|
WO |
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Other References
International Search Report for International PCT Patent
Application No. PCT/EP2015/057367 dated Jul. 3, 2015. cited by
applicant .
Henry Lee and Kris Neville, Handbook of Epoxy Resins, chapter 7,
pp. 7-1 to 7-33 McGrawHill Book company New York 1967. cited by
applicant .
Clayton A. May, Epoxy Resins, pp. 466-469, Marcel Dekker, New York
1988. cited by applicant .
Henry Lee and Kris Neville, Handbook of Epoxy Resins, chapter 10,
pp. 10-1 to 10-23 McGrawHill Book company New York 1967. cited by
applicant .
Matyjaszewski, K. Hrsg., Cationic Polymerizations: Mechanisms,
Synthesis, and Applications (in: Plast. Eng. (N. Y.), 1996, 35,
Dekker. cited by applicant .
M. Sangermano, N. Razza and J. V. Crivello (Macromol. Mater. Eng.,
2014, 299, S. 775-793). cited by applicant .
PEG-based Multifunctional Polyethers with Highly Reactive
Vinyl-Ether Side Chains for Click-Type Functionalization;
Macromolecules vol. 44, Issue: 16, pp. 6326-6334. cited by
applicant .
Kayaman-Apohan et al., Synthesis and characterization of UV-curable
vinyl ether functionalized urethane oligomers, Progress in Organic
Coatings 49 (2004), 23-32. cited by applicant.
|
Primary Examiner: Woodward; Ana L.
Attorney, Agent or Firm: Piotrowski; James E.
Claims
The invention claimed is:
1. A two component binder system containing resin component (A) and
curing agent component (B), wherein: (i) Component (A) comprises at
least one compound containing at least two cyclic carbonate groups
and at least one compound containing at least two epoxy groups; and
(ii) Component (B) comprises: a first compound containing at least
two (--NHR--) atomic groups and having a molecular weight of 60
g/mol to 500 g/mol, and a second compound containing at least two
(--NHR--) atomic groups and having a molecular weight of greater
than 500 g/mol, wherein R is H, an alkyl or aryl radical.
2. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
polymer containing cyclic carbonate groups selected from the group
consisting of optionally alkoxylated castor oil, optionally
alkoxylated dimer diol, polyethers, polyether polyols, polyesters,
polyester polyols, polycarbonates, polycarboxylic acids,
polyacrylates, polymethacrylates, polyamides, polyamines,
polyurethanes, and mixtures thereof.
3. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
reaction product of cyclic hydroxyalkyl carbonate with a polymer
containing isocyanate groups.
4. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
reaction product of cyclic hydroxyalkyl carbonate having a
five-membered or six-membered carbonate ring with a polymer
containing isocyanate groups.
5. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
reaction product of a glycerin carbonate with a polymer containing
isocyanate groups.
6. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
reaction product of cyclic hydroxyalkyl carbonate with an
isocyanate group-terminated polyurethane prepolymer that is the
reaction product of a polyol with an aromatic diisocyanate.
7. The binder system according to claim 1, wherein the at least one
compound containing at least two cyclic carbonate groups is a
reaction product of cyclic hydroxyalkyl carbonate with an
isocyanate group-terminated polyurethane prepolymer that is the
reaction product of a polyol with an average molecular weight Mw of
75 to 2000 g/mol with methylene diphenyl diisocyanate.
8. The binder system according to claim 1, wherein the compound
containing at least two epoxy groups is an aliphatic epoxy.
9. The binder system according to claim 1, wherein the compound
containing at least two epoxy groups is an aliphatic epoxy with an
EEW of 120 to 350 g/mol.
10. The binder system according to claim 1, wherein the first and
second compounds of Component (B) are: (i) selected from the group
consisting of alkylene diamines, cycloalkylene diamines,
amine-functionalized polyalkylene glycols, and polyfunctional
amines; (ii) a polymer or a highly branched polymer or a dendrimer,
selected from the group consisting of polyamines, polyimines,
polyethers, polyamides, polyaminoamides, polyurethanes,
polyolefins, polyvinyl amines, and mixtures thereof; or (iii) a
mixture of the compounds according to (i) and (ii).
11. A cured reaction product of a mixture comprising Component (A)
and Component (B) of claim 1.
12. A two-component adhesive comprising the binder system of claim
1.
13. A two-component adhesive comprising the binder system of claim
1, wherein the adhesive is solvent-free.
14. A two-component adhesive comprising the binder system of claim
1, wherein the adhesive further comprises solvent.
15. A food package comprising a laminate of at least two films with
the binder system of claim 1 disposed therebetween.
16. A food package comprising a laminate of at least two films
bonded together by cured reaction products of an adhesive
comprising the binder system of claim 1.
17. A method for producing an adhesive or sealant using the binder
system of claim 1, comprising: providing the binder system of claim
1; mixing component (A) with component (B) in a ratio of carbonate
groups to primary amino groups of 30:1 to 0.2:1, wherein the mixing
ratio is to be applied to secondary amino groups in the absence of
primary amino groups.
18. A method for producing an adhesive or sealant using the binder
system of claim 1, comprising: providing the binder system of claim
1; mixing component (A) with component (B) in a ratio of carbonate
groups to primary amino groups of 5:1 to 0.5:1, wherein the mixing
ratio is to be applied to secondary amino groups in the absence of
primary amino groups.
19. A method for producing an adhesive or sealant using the binder
system of claim 1, comprising: providing the binder system of claim
1; and mixing component (A) with component (B) in a ratio of
carbonate groups to primary amino groups of about 1:1, wherein the
mixing ratio is to be applied to secondary amino groups in the
absence of primary amino groups.
20. The binder system according to claim 1, wherein the first
compound containing at least two (--NHR--) atomic groups has a
molecular weight of 60 g/mol to 300 g/mol.
21. The binder system according to claim 20, wherein the second
compound containing at least two (--NHR--) atomic groups has a
molecular weight of 500 g/mol to 5,000,000 g/mol.
22. The binder system according to claim 21, wherein the second
compound containing at least two (--NHR--) atomic groups has a
molecular weight of 600 g/mol to 20,000 g/mol.
Description
The present invention relates to a binder system comprising a resin
component and a curing agent component, wherein the resin contains
at least one compound having at least two cyclic carbonate groups
and at least one compound having at least two epoxy groups, and the
curing agent comprises at least one multifunctional amine as well
as the use of the binder system as an adhesive/sealant and the use
of this adhesive/sealant.
Two-component binder systems, in particular those based on polyols
and NCO-terminated compounds, have long been known in the state of
the art. They are used as adhesives, sealing compounds, fillers or
casting compounds (casting), for example, in the field of the
metalworking industry, the automotive industry, the electronics
industry, the packaging industry or the construction industry. One
disadvantage of the polyurethanes having NCO groups that are used
as the so-called resin is their sensitivity to moisture. Therefore,
tight containers must be used accordingly when storing these
compounds. Once a container has been opened, it must be consumed
immediately in most cases, i.e., within a short period of time, to
avoid a loss of quality. The polyol component must also be dried
carefully in most cases before being mixed with the resin component
because otherwise a residual amount of moisture can lead to
unwanted blistering in the adhesive film, which causes
disadvantages in final application under some circumstances.
Another disadvantage of at least some binder systems based on
two-component polyurethane adhesives is the toxicology of monomeric
isocyanates, in particular readily volatile and/or readily
migrating monomeric isocyanates, in the resin component. The use of
products containing a large amount of readily volatile
diisocyanates requires extensive occupational safety measures on
the part of the user, in particular complex measures for keeping
the respiratory air clean, as prescribed by law, due to the maximum
allowed concentration of occupational substances in the form of a
gas, vapor or particulate matter suspended in the air at the job
site (MAC--Maximum Allowed Concentration--list, updated annually,
of the Technical Rule TRGS 900 of the Federal Ministry of Labor and
Social Affairs).
However, free monomeric polyisocyanates can also "migrate" into the
coating or bonding or to some extent may also migrate into the
coated or glued materials. Such migrating components are often
referred to in technical circles as "migrates." Through contact
with moisture, the isocyanate groups of the migrates are converted
continuously to amino groups.
In the packaging field, in particular in food packagings, migrates
are particularly unwanted. On the one hand, the migration of the
migrates through the packaging material can result in contamination
of the packaged material. On the other hand, long waiting times are
necessary before the packaging material is "migrate-free" and may
be used, depending on the amount of free monomeric polyisocyanate
that can migrate.
Another unwanted effect that may be caused by migration of
monomeric polyisocyanates is the so-called anti-sealing effect in
the production of bags or packets of laminated plastic films: the
laminated plastic films often contain lubricants based on fatty
acid amides. By reaction of migrated monomeric polyisocyanate with
fatty acid amide and moisture, urea compounds that are formed on
the surface of the film have a melting point which may be higher
than the sealing temperature of the plastic films. This results in
an atypical anti-sealing layer between the film parts to be sealed,
counteracting a uniform sealing seam formation.
Products based on compounds containing cyclic carbonate groups and
aliphatic polyamines are known in principle from WO 2006/010408,
for example. Although the products described therein overcome the
aforementioned disadvantages, while at the same time having good
adhesive/sealing properties, they also require high curing
temperatures of at least 80.degree. C., with the average tending to
be around 100.degree. C. which is a disadvantage for certain
applications or may even make them impractical. However, at lower
temperatures, such as 40.degree. C., for example, curing is
incomplete and adhesion later is too low.
The object of the present invention was therefore to make available
a binder system that would overcome these disadvantages and would
enable adequate curing even at low temperatures and would exhibit
good adhesion properties.
The inventors have surprisingly found that this object can be
achieved by a binder system and that an epoxy resin component can
be used in addition to a resin component containing cyclic
carbonate groups. The binder systems obtained in this way exhibit
complete curing at temperature of 40.degree. C. with adhesion
properties comparable to those of known systems.
In a first aspect, the invention therefore relates to a binder
system containing the components (A) and (B), wherein component (A)
comprises at least one compound having at least two cyclic
carbonate groups and at least one compound having at least two
epoxy groups; and component (B) comprises at least one compound
having at least two (--NHR--) atomic groups, wherein R is H, an
alkyl or aryl radical. The alkyl radical may be linear or branched,
saturated or mono- or polyunsaturated, substituted or unsubstituted
and has in particular 1 to 30 carbon atoms. The aryl radical may be
monocyclic or polycyclic, substituted or unsubstituted and has 6 to
22 carbon atoms in particular.
In another aspect, the invention relates to methods for producing
an adhesive/sealant using the binder system described herein. In
this variant the component (A) is mixed with component (B) in a
ratio of carbonate groups to primary amino groups of 30:1 to 0.2:1,
preferably 10:1 to 0.4:1, more preferably 5:1 to 0.5:1, especially
preferably 2:1 to 0.6:1, in particular preferably 1.1:1 to 0.9:1
and most preferably approx. 1:1. IN the absence of primary amino
groups, this mixing ratio is to be applied to secondary amino
groups.
In yet another aspect, the invention relates to the use of the
binder system described herein as a two-component adhesive for
adhesive bonding of paper, cardboard, wood, plastic, metal or
stoneware, in particular as a solvent-free or solvent-containing
lamination adhesive or for producing casting compounds.
Finally the invention also relates to methods for producing film
laminates, wherein at least two plastic films that are the same or
different are bonded together over all or part of the surface using
a binder system described herein, as well as the film composite
produced in this way.
The molecular weights given in the present text refer to the
weight-average molecular weight (Mw), unless otherwise indicated.
All molecular weight specifications refer to values such as those
obtained by gel permeation chromatography (GPC) according to the
standard DIN 55672-1:2007-08 unless otherwise indicated.
"At least one," as used here denotes one or more, i.e., 1, 2, 3, 4,
5, 6, 7, 8, 9 or more. Based on one ingredient, this specification
refers to the type of ingredient and not the absolute number of
molecules. "At least one polyol" thus denotes, for example, at
least one type of polyol, i.e., a type of polyol or a mixture of
several different polyols may be used. Together with weight
specifications, the specification refers to all compounds of the
stated type, which are contained in the composition/mixture, i.e.,
the composition does not contain any other compounds of this type
beyond the specified amount of the corresponding compounds.
All percentage amounts specified in conjunction with the
compositions described herein refer to % by weight (wt. %), unless
otherwise indicated, always based on the respective mixture.
"Approximately" or "approx." as used herein in conjunction with a
numerical value refers to the numeral value .+-.10%, preferably
.+-.5%,
It has, surprisingly, been found that the binder systems described
herein have an essentially complete conversion even at
comparatively low temperatures, are suitable as adhesives/sealants
and are characterized by a good adhesion to surfaces of a wide
variety of materials. The essentially NCO group-free polyurethane
adhesives/sealants may be used in substance or in solution in
conventional organic solvents. "Essentially free of NCO groups"
means that the NCO content in components (A) <0.1% by weight
(determined according to Spiegelberger, EN ISO 1909:2007-05).
Any polymers may be used as the at least one compound having at
least two cyclic carbonate groups as long as they do not have any
other functional groups which could interfere with the reaction
with component (B). The at least one compound containing at least
two cyclic carbonate groups may be both linear and branched. As
already mentioned, the term "at least one" in this context means
that the binder system may contain one or more compounds, each of
which has at least two cyclic carbonate groups. "At least two
cyclic carbonate groups" means that the compounds have two or more
but preferably exactly two cyclic carbonate groups, in particular
terminal groups.
The cyclic carbonate groups are preferably disposed on the polymer
chain ends but in many cases it is also possible to use compounds
containing these groups in random distribution over the entire
polymer chain. The cyclic carbonate groups may thus be built into
the main chain as well as being disposed in a side position.
The compound having at least two cyclic carbonate groups is
preferably a polymer, the polymer being selected from the group of
fat chemical compounds, polyethers, polyether polyols, polyesters,
polyester polyols, polycarbonates, polycarboxylic acids,
polyacrylates, polymethacrylates, polyamides, polyamines,
polyurethanes or mixtures thereof. The preferred fat chemical
compounds include castor oil or dimer diol which are also
alkoxylated. Especially preferred within the context of this
invention are polyurethanes.
Polyamides are understood to be those which do not have any amine
NH groups.
Cyclocarbonates, which may also be referred to as cyclic
carbonates, are to be understood as structures in which a carbonic
acid ester group is part of a ring structure according to formula
(I):
##STR00001##
wherein
A is (C(R.sup.1R.sup.2).sub.n, where n>2, preferably n=2 or 3,
in particular preferably n=2; R.sup.1, R.sup.2 are each selected
independently of one another from hydrogen, a saturated or
unsaturated, linear or branched or cyclic aromatic or aryl
aliphatic, optionally substituted hydrocarbon radical with 1 to 12
carbon atoms, an ether radical with 1 to 12 carbon atoms and up to
three oxygens, R.sup.3X, where R.sup.3 is a divalent aliphatic,
cycloaliphatic aromatic aryl aliphatic or ether-containing,
optionally substituted hydrocarbon radical with 1 to 20 carbon
atoms and X is a hydroxy, epoxy, carboxylic acid or carboxylic acid
ester group, or Z, wherein Z is an unsaturated polymerizable group,
in particular a vinyl, (meth)acryl, maleic acid, fumaric acid,
itaconic acid or crotonic acid ester group.
Specific examples of cyclocarbonates include, without being limited
to, ethylene carbonate (1,3-dioxolan-2-one); propylene carbonate
(4-methyl-1,3-dioxolan-2-one); glycerin carbonate
(4-methylhydroxy-1,3-dioxolan-2-one);
5-ethyl-5-(hydroxymethyl)-1,3-dioxan-2-one; 1,3-dioxan-2-one,
5-(allyloxy)methyl)-5-ethyl-1,3-dioxan-2-one or 1,3-dioxepin-2-one.
Cyclic carbonates having epoxy groups are described in DE 3726497
A1, for example.
Cyclic carbonates are obtained, for example, by transesterification
of carbonic acid esters such as, for example, dimethyl carbonate,
diethyl carbonate, diphenyl carbonate, ethylene carbonate or
propylene carbonate with polyols, wherein the polyols preferably
have at least three hydroxyl groups, two of which react with
carbonic acid esters in a transesterification reaction to form
cyclic five-membered or six-membered carbonates. Examples of
polyvalent polyols that can be mentioned include glycerol,
diglycerol, triglycerol, polyglycerol, sugar alcohols (for example,
xylitol, mannitol, erythritol), di- and trimethylolpropane, di- and
trimethylolethane, pentaerythritol, dipentaerythritol. Glycerol is
especially preferred here. The cyclic carbonates are synthesized
from the polyols by methods with which those skilled in the art are
familiar, in particular by reacting the polyols with the carbonates
in a stoichiometric ratio of 1.0:1.0 to 1.0:10.0 (ratio of 1,2- or
1,3-glycol groups to form carbonate groups), in particular with
catalysis. Examples of suitable catalysts include basic catalysts
such as, for example, carbonates, bicarbonates, alcoholates,
carboxylates, hydroxides or oxides of the alkali and alkaline earth
metals as well as Lewis acid substances, for example, organic
compounds of divalent or trivalent tin or titanium, for example,
tin(II) octoate, tin(II) laureate, dibutyltin oxide or titanium
tetrabutylate. The catalysts may be added in an amount of 0.01 to
1.0% by weight, based on polyol and carbonic acid esters, for
example.
Cyclic carbonates can also be obtained by reacting carbon dioxide
with epoxy compounds in the known manner. Conversion reactions are
described, for example, in WO 84/03701, DE-A 3529263 or DE-A
3600602.
By reacting polyols with phosgene, both aliphatic and aromatic
cyclic carbonates can be obtained (e.g., U.S. Pat. No.
3,624,016).
Furnishing the polymer with at least two cyclic carbonate groups,
hereinafter referred to as functionalization, may take place during
the synthesis of the polymer chain, wherein corresponding monomer
building blocks containing cyclocarbonate groups may be used.
However, it is preferable to subsequently functionalize a polymer
that has already been synthesized. Especially preferred here is
addition of cyclic hydroxyalkyl carbonates onto polymers having
anhydride groups or isocyanate groups. In principle, a
corresponding method is described in EP 0328150 A2. Cyclic
hydroxyalkyl carbonates with five-membered or six-membered
carbonate rings are preferred for use in the addition reaction.
Glycerin carbonate is most especially preferred. It is likewise
possible to react such cyclic hydroxyalkyl carbonates by
transesterification, in which C.sub.1-C.sub.4 alkyl ester groups of
the polymer, for example, may be reacted directly or it is possible
to react hydroxyl groups of the polymers with an ester groups of a
low-molecular C.sub.2 to C.sub.6 dicarboxylic acid ester and then
react the remaining C.sub.1-C.sub.4 alkyl ester groups with a
hydroxyalkyl carbonate. Low-molecular dicarboxylic acid esters are
understood to be those in which the dicarboxylic acid radical is
constructed from 2 to 44 carbon atoms, preferably 2 to 12 carbon
atoms, especially preferably 2 to 6 carbon atoms and may have a
linear or branched aliphatic, cycloaliphatic or aromatic structure.
Another possibility for inducing hydroxyalkyl carbonates to react
is their reaction with acid halides, in particular carboxylic acid
halides.
In another embodiment of the invention, examples of compounds
having at least two cyclic carbonate groups include those obtained
by addition of carbon dioxide onto polymers containing epoxy
groups. In principle, such an addition method is described in
Unexamined German Publications DE-OS 3529263 and/or DE-OS
3600602.
Due to the choice of the basic compound and the choice of the
functionalization with the cyclic carbonate groups, it is possible
to obtain polymers containing urethane groups or only ester groups.
It is possible in this way to influence the viscosity of the
polymer.
Polyurethanes functionalized with at least two cyclic carbonate
groups are preferred. The cyclic carbonate groups are arranged at
the termini in particular. Such functionalized polymers are
produced in a two-step synthesis. In a first step, a polyol or a
polyol mixture with a stoichiometric excess of polyisocyanate is
reacted to obtain an NCO-terminated polyurethane prepolymer, which
is then functionalized with the cyclic carbonate groups in a second
step, for example, by reacting a cyclic hydroxyalkyl carbonate, in
particular one having a five-membered or six-membered carbonate
ring, most especially preferably glycerin carbonate, with the
terminal isocyanate groups.
It is therefore preferable for the compound having at least two
cyclic carbonate groups to be the reaction product of a polymer
containing an isocyanate group, in particular an isocyanate
group-terminated polyurethane prepolymer with a hydroxyalkyl
carbonate, in particular one having a five-membered or six-membered
carbonate ring, most especially preferably glycerin carbonate.
The polyols used in the synthesis of the polymer may all be the
polyols generally used for polyurethane synthesis, for example,
polyester polyols or polyether polyols, in particular polyether
polyols such as polypropylene glycol or polyethylene glycol. The
polyols used preferably have an average molecular weight (Mw) of 60
to 4000 g/mol, preferably 75 to 2000 g/mol.
The polyisocyanates used are in particular diisocyanates,
especially preferably aromatic diisocyanates. Example of suitable
diisocyanates include methylene diphenyl diisocyanates (MDI) such
as 4,4'-methylene diphenyl diisocyanate, 2,4'-melthylene diphenyl
diisocyante or 2,2'-methylene diphenyl diisocyanate as well as
mixtures thereof.
The at least one compound having at least two cyclic carbonate
groups is therefore preferably a cyclocarbonate-terminated
polyurethane prepolymer of a polyether polyol and an aromatic
diisocyanate such as MDI.
The molecular weight (Mw) of the at least one compound having at
least two cyclic carbonate groups is preferably from 1500 g/mol to
100,000 g/mol, in particular preferably 2000 g/mol to 50,000
g/mol.
In a further embodiment, a further low-molecular compound
containing cyclic carbonate groups may also be present in the
bonder system. This component should have a molecular weight (Mw)
<1000 g/mol, preferably <800 g/mol and should contain at
least two cyclic carbonate groups. These may be, for example,
diepoxies reacted with CO.sub.2 or di- or tricarboxylic acid esters
that have been reacted at the ester groups with the aforementioned
hydroxy-functional cyclic carbonates. Components of this type are
also referred to as reactive diluents and may be added in amounts
of up to 60% by weight, preferably up to 25% by weight, based on
(A) to influence the viscosity of the binder system.
Component (A) additionally contains at least one compound having at
least two epoxy groups. The compounds that can be used herein are
preferably epoxy resins, for example, polyglycidyl epoxy compounds
or epoxy novolacs. Suitable polyglycidyl epoxies include, without
being limited to, polyglycidyl ethers,
poly(.beta.-methylglycidyl)ethers, polyglycidyl esters and
poly(.beta.-methylglycidyl)esters and mixtures of the
aforementioned epoxy resins. Suitable polyglycidyl ethers or esters
include, for example, diglycidyl ethers or esters of aliphatic
diols or dicarboxylic acids. Also suitable are cycloaliphatic epoxy
resins such as, for example, (di)ethers or (di)esters based on
3,4-epoxycyclohexylmethanol.
The at least one epoxy resin is selected from various embodiment
from diglycidyl ethers based on propylene glycol or ethylene
glycol.
It is preferred in general for the compound having at least two
epoxy groups to be an aliphatic epoxy. Epoxies having an epoxy
equivalent weight (EEW, epoxy equivalent weight) of 100 to 500
g/mol, preferably 120 to 350 g/mol are preferred. The EEW refers to
the weight of epoxy compound containing 1 mol epoxy groups. It can
be determined according to the standard DIN EN ISO
3001:1999-11.
The amount of epoxy in component (A) is preferably 5 to 30% by
weight, based on the total amount of solids (cyclocarbonate
compound and epoxy). Accordingly, the cyclocarbonate compound is
present in an amount of 70 to 95% by weight, based on the total
amount of solids.
In addition to component (A), the binder system according to the
invention contains at least one multifunctional amine, i.e., at
least one compound having at least two (--NHR--) atomic groups or a
mixture of two or more compounds having at least two (--NHR--)
atomic groups as component (B), where R.dbd.H, alkyl or aryl
radical.
The compounds of component (B) may be both linear and branched. The
molecular structure of component (B) may contain aliphatic,
aromatic, aliphatic aromatic, cycloaliphatic and heterocyclic
structures. Primary and/or secondary and tertiary amines may be
present in the molecule, but at least two (--NHR--) atomic groups
must be present, preferably two amino groups. The amine functions
per se are aliphatic, i.e., the carbon atoms directly vicinal to
the amine nitrogen are not part of an aromatic ring structure.
Component (B) preferably contains a multifunctional amine as
component (B1), in particular having a molecular weight (Mw) of 60
g/mol to 500 g/mol, preferably from 60 g/mol to 300 g/mol and/or a
multifunctional amine as component (B2), in particular with an
average molecular weight (Mw) of >500 g/mol. Mixtures of (B1)
and (B2) are especially preferred. The weight ratio of (B1) to (B2)
in the mixtures of (B1) with (B2) that are used is 0.5:20 to
20:0.5. The upper limit of the molecular weight (Mw) of component
(B2) is approx. 5,000,000 g/mol. Component (B2) preferably has an
average molecular weight (Mw) of 600 g/mol to 20,000 g/mol, in
particular preferably 800 g/mol to 2000 g/mol.
Component (B1) is used as a single component or as a mixture of the
corresponding compounds that can be used as component (B1).
Component (B1) is preferably selected from the group of alkylene
diamines and/or cycloalkylene diamines.
Alkylene diamines are understood to be compounds of the general
formula R.sup.4R.sup.5N--Z--NR.sup.6R.sup.7 in which R.sup.4,
R.sup.5, R.sup.6 and R.sup.7, independently of one another, may be
H, alkyl or cycloalkyl radicals. Z denotes a linear or branched,
saturated or unsaturated alkylene chain having two or preferably
more than two carbon atoms. Preferred examples include
diaminoethane, diaminopropane, 1,2-diamino-2-methylpropane,
1,3-diamino-2,2-dimethylpropane, diaminobutane, diaminopentane,
1,5-diamino-2-methylpentane, neopentyl diamine, diaminohexane,
1,6-diamino-2,2,4-trimethylhexane,
1,6-diamino-2,4,4-trimethylhexane, diaminoheptane, diaminooctane,
diaminononane, diaminodecane, diaminoundecane, diaminododecane,
dimer amine (known commercially, for example, under the brand names
Versamin 551 from Cognis and/or BASF), triacetone diamine,
dioxadecane diamine, N,N-bis(3-aminopropyl)dodecylamine (available
commercially, for example, under the brand name Lonzabac 12.30 from
Lonza) or mixtures thereof.
Cycloalkylene diamines are to be understood as compounds of the
general formula R.sup.8R.sup.9N--Y--NR.sup.10R.sup.11, in which
R.sup.8, R.sup.9, R.sup.10 and R.sup.11 independently of one
another may be H, alkyl or cycloalkyl radicals. Y denotes a
saturated or unsaturated cycloalkyl radical with more than three
carbon atoms, preferably more than four carbon atoms.
Diaminocyclopentanes, diaminocyclohexanes, diaminocycloheptanes,
for example, 1,4-cyclohexanediamine,
4,4'-methylene-biscyclohexylamine,
4,4'-isopropylene-biscyclohexylamine, isophorone diamine,
m-xylylene diamine, N-aminoethylpiperazine or mixtures thereof.
The diamines may also contain both alkyl radicals and cycloalkyl
radicals together. Preferred examples include aminoethylpiperazine,
1,8-diamino-p-menthane, isophorone diamine,
1,2-(bisaminomethyl)cyclohexane, 1,3-(bisaminomethyl)cyclohexane,
1,4-(bisaminomethyl)cyclohexane and
bis-(4-aminocyclohexyl)methane.
Additional examples of diamines that can be used for component (B1)
according to the invention include bis-(6-aminohexyl)amine,
.alpha.,.alpha.'-diaminoxylols, etc.
Highly functional amines are preferably used as component (B1)
and/or component (B2). In particular these are the
amino-functionalized polyalkylene glycols, such as
1,2-bis-(aminoethoxy)ethane, 1,13-diamino-4,7,10-trioxatridecane.
Amine-functionalized polyalkylene glycols that can be used
according to the invention include those available commercially as
Jeffamine.RTM. from Huntsman Corp. The preferred Jeffamines are
D-230, D-400, D-2000, D-4000, T-403, T-3000, T-5000, ED-600,
ED-2003.
Polyfunctional amines that can also preferably be used as component
(B1) and/or component (B2) are compounds of the general formula
H.sub.2N--(CH.sub.2CH.sub.2--NH).sub.x--CH.sub.2CH.sub.2--NH.sub.2,
where 1<x<10 such as diethylenetriamine,
triethylenetetramine, tetraethylenepentamine,
pentaethylenehexamine, dipropylenetriamine,
bis-(3-aminopropyl)amine, N,N-bis(3-aminopropyl)ethylenediamine,
bishexamethylenetriamine, heptaethylenoctamine and the like.
Polymers selected from the group consisting of polyamines,
polyimines, polyethers, polyamides, polyaminoamides, polyurethanes,
polyolefins, polyvinyl amines or mixtures thereof are preferred for
use as component (B2).
Polyamines that can be used as component (B2) are described by
Henry Lee and Kris Neville, Handbook of Epoxy Resins, chapter 7,
pages 7-1 to 7-33, McGraw-Hill Book Company, New York 1967 and the
literature cited there as well as by Clayton A. May, Epoxy Resins,
pages 466-468, Marcel Dekker, New York 1988 and the literature
cited there.
Preferred polyimines include polyethyleneimines. The amine hydrogen
functions of the polyethyleneimines may also be partially modified
such as, for example, by alkylation, benzylation, acylation,
alkoxylation, preferably ethoxylation and/or propoxylation.
Modification with epichlorohydrin is particularly preferred.
Polyethyleneimines that can preferably be used are available
commercially from BASF under the brand names Lupasol.RTM. PS, P,
WF, Bo 150, FC, FG, G100, G-20, G-35, G-500, HF, PO-100, PR-8515
and SK or as obtained from DOW under the brand names
Polyethylenimin 6, 12, 18, 600 and 1000.
Polyaminoamides contain both amine and amide functionalities in the
main chain. Polyaminoamides are synthesized by polycondensation of
polyamines and dicarboxylic acids or by Michael addition of acrylic
acid esters onto diamines and subsequent polycondensation of the
resulting amine acid esters. Polyaminoamides that can be used as
component (B2) are described by Henry Lee and Kris Neville,
Handbook of Epoxy Resins, chapter 10, pages 10-1 to 10-23,
McGraw-Hill Book Company, New York 1967 as well as by Clayton A.
May, Epoxy Resins, pages 469, Marcel Dekker, New York 1988 and the
literature cited there.
Within the scope of the present invention, polyaminoamides that are
obtained by polycondensation of aliphatic polyamines and dimerized
or trimerized fatty acids are preferably used. Grafted and
ungrafted polyaminoamides such as those described in WO 94/29422
may also be used. Polyaminoamides from Cognis and/or BASF are
commercially available under the brand names Versamid.RTM. from
Bakelite AG under the brand names Ruetadur or the company S.I.Q.
Kunstharz GmbH from the SIQTherm product series.
Additional polyamines that can preferably be used as component (B2)
include polyvinylamines. Polyvinylamines may be synthesized, for
example, by polymerization of N-vinylacylamines such as
N-vinylformamide, N-vinylacetamide, etc. and subsequent complete or
partial hydrolysis of the amide group. Polyvinylamines that may
preferably be used are available commercially from the company BASF
under the brand names Lupamin.RTM.: 1500, 4500, 4595, 9000, 9030,
9095. Amine-terminated polyether urethanes are available, for
example, from Henkel under the brand names Loctite Liofol UR
9640.
Additional polyamines that may be used as component (B2) include
highly branched polymers having amino groups, in particular primary
amino groups on the branch termini.
A group of highly branched polymers that are particularly preferred
as component (B2) includes the dendritic polymers, which are also
referred to as dendrimers, cascade polymers or "starburst"
polymers. These are understood to be synthetic macromolecules that
are constructed step by step by linking two or more monomers with
each monomer that has already been bound so that with each step the
number of monomer end groups increases exponentially and at the end
the result is a spherical tree structure. Preferred dendrimers
include polyaminoamides (PAMAM) having primary amino functions on
the branch ends. Those of the generation >0 are preferred.
General 0 is understood to refer to dendrimers of the following
structure:
[--CH.sub.2N(CH.sub.2CH.sub.2CONHCH.sub.2CH.sub.2NH.sub.2).sub.2].sub.2,
Especially preferred are dendrimers of the generation >1,
wherein dendrimers of generation 1 have the following structure:
[--CH.sub.2N[CH.sub.2CH.sub.2CONHCH.sub.2CH.sub.2N(CH.sub.2CH.sub.2CONHCH-
.sub.2CH.sub.2NH.sub.2).sub.2].sub.2].sub.2
The structures of the higher generations, preferably up to
generation 6, are derived from the above systematic creation of
generation 0 to generation 1.
Dendrimers can be synthesized, for example, by stepwise reaction of
ammonia or suitable representatives of the aforementioned alkylene
diamines of the general formula R.sup.4R.sup.5N--Z--NR.sup.6R.sup.7
with acrylic acid esters. R.sup.4--R.sup.7 in these cases stands
for hydrogen. Z is a linear or branched saturated or unsaturated
alkylene chain with two or more carbon atoms. The polymer structure
is created by Michael addition of the amino groups onto the
olefinic double bonds and condensation of amino groups with ester
groups. A suitable molar excess of amines is to be selected.
Additional suitable amine components for the dendrimer structure
can be found in the aforementioned groups of cycloalkylene
diamines, diamines having both alkyl radical and cycloalkyl
radicals and the group of amine-functionalized polyalkylene
glycols. All the amine components in question have two primary
amino functions in these cases.
Another preferred group of highly branched polymers that are used
as component (B2) is formed, for example, by stepwise reaction of
acrylic acid esters with suitable representatives of the
aforementioned polyfunctional amines of the general formula
H.sub.2N--(CH.sub.2CH.sub.2--NH)X--CH.sub.2CH.sub.2--NH.sub.2,
where 1<x<10, such as diethylenetriamine,
triethylenetetramine, tetraethylenepentamine and
pentaethylenehexamine, for example.
The component (B2) that can be used according to the invention may
also be synthesized by reaction of an excess of the aforementioned
low-molecular polyfunctional amines that can be used as component
(B1) with cyclic carbonates having an average molecular weight (Mw)
of less than 1000 g/mol, preferably of 100 g/mol to 800 g/mol. In
these cases, a suitable molar excess of amine in relation to the
cyclocarbonate is to be selected so that, on the one hand, the
desired molecular weight is achieved, while additionally the amine
functionality according to the invention is present for use as
component (B2).
Component (B2) is used as a single component or as a mixture of the
corresponding compounds that can be used as component (B2).
The binder system described herein is suitable in particular as an
adhesive/sealant.
The subject matter of the present invention is therefore also a
method for synthesis of an adhesive/sealant using the binder system
described herein, wherein component (A) is mixed with component (B)
in a ratio of carbonate groups to primary amino groups of 30:1 to
0.2:1, preferably 10:1 to 0.4:1, more preferably from 5:1 to 0.5:1,
especially preferably from 2:1 to 0.6:1 and most preferably
approximately 1:1. If no primary amino groups are present in the
molecule, then the ratio is to be applied to the secondary amino
groups. The functional groups of components (A), (B1), (B2) are to
be taken into account on the whole.
In a preferred embodiment of the method described herein, the
reaction takes place between component (A) and component (B) in the
presence of a solvent.
Fundamentally all solvents known to those skilled in the art may be
used as the solvent here, in particular ketones, halogenated
hydrocarbons, alkanes, alkenes and aromatic hydrocarbons. Examples
of such solvents include methylene chloride, trichloroethylene,
toluene, xylene, butyl acetate, amyl acetate, isobutyl acetate,
methyl isobutyl ketone, methoxybutyl acetate, cyclohexane,
cyclohexanone, dichlorobenzene, diethyl ketone, diisobutyl ketone,
dioxane, ethyl acetate, ethylene glycol monobutyl ether acetate,
ethylene glycol monoethyl acetate, 2-ethyihexylacetate, glycol
diacetate, heptane, hexane, isobutyl acetate, isooctane, isopropyl
acetate, methyl ethyl ketone, tetrahydrofuran or
tetrachloroethylene or mixtures of two or more of the
aforementioned solvents.
In a special embodiment of the method described herein, the
reaction between component (A) and component (B) takes place with
catalysis. To do so, catalytic amounts of a base are added to the
mixture. Such bases and the amount to be used are described in U.S.
Pat. No. 5,977,266 and WO 02/079148. Reference is made in
particular to WO 98/50345, page 3, line 1 to page 4, line 17.
However, the catalyst may also be already present in component (A)
or (B). For adhesive bonding or sealing, at least one side of a
substrate to be bonded or sealed is coated with the mixture and the
side thereby coated is joined to at least one additional
substrate.
The binder system described herein is suitable for adhesive bonding
and sealing of a wide variety of substrates. These substrates
include, for example, wood, metal, glass, plant fibers, stone,
brick, paper, cellulose hydrate, plastics such as polystyrene,
polyethylene, polypropylene polyethylene terephthalate, polyvinyl
chloride, copolymers of vinyl chloride and vinylidene chloride,
copolymers of vinyl acetate olefins, polyamides, in particular
plastic films, metals, in particular films of aluminum, lead or
copper.
The binder system described herein is particularly suitable as a
two-component adhesive for adhesive bonding of paper, cardboard,
wood, plastic, metal or masonry.
In a particularly preferred embodiment of the invention, the binder
system described herein is used as a solvent-free or solvent-based
lamination adhesive. The lamination adhesive is preferably
essentially solvent-free, in particular essentially free of
water.
The binder system described herein can be applied to the substrates
to be bonded by using all conventional application methods, for
example, by spraying, doctor application, three-four-roller
application systems in the case of use of a solvent-free binder
system or two-roller application systems in the case of use of a
solvent-based binder system.
Due to its low viscosity, the binder system described herein is
suitable in particular for adhesive binding of
temperature-sensitive plastic films, for example, polyolefin films,
in particular polyolefin films made of polyethylene or
polypropylene.
Another subject matter of the present invention is therefore also a
method for manufacturing film laminates that can be obtained by
adhesive bonding of at least two plastic films that are the same or
different over a partial area or the full area, using the binder
system described herein. The binder system may be applied as a
two-component adhesive to the films to be bonded using the machines
conventionally used for such purposes, for example, traditional
lamination machines. Another subject matter of the invention is a
laminate film produced by the method described herein, using the
binder system described herein. The laminated film is suitable in
particular for packaging foods and luxury items as well as
pharmaceutical drugs.
The binder system described herein may contain the usual additives
such as plasticizers, silanes, antioxidants, UV stabilizers and
antiaging agents. Plasticizers preferred for use here include
phthalic acid esters, for example, dioctyl phthalate, ditridecyl
phthalate and butylbenzyl phthalate, phosphoric acid esters such
as, for example, tricresyl phosphate, adipates, for example,
dioctyl adipate or benzoates, for example, propylene glycol
dibenzoate.
Aminosilanes, epoxysilanes or mercaptosilanes, in particular
.gamma.-glycidyloxypropyl trimethoxysilane or .gamma.-aminopropyl
trimethoxysilane, are used in particular to improve adhesion to
glass, metals, etc.
For use as a sealing compound, inorganic fillers such as carbon
black, calcium carbonate, titanium dioxide and the like may be
added to the binder systems described herein. Highly dispersed
silicic acids, in particular pyrogenic silicic acids or
precipitated silicic acids are preferably used as the inorganic
fillers which have a thixotropic effect and whose thixotropic
properties are also maintained in the binder systems described
herein, even after prolonged storage.
For use as a lamination adhesive, the binder system is preferably
free of inorganic fillers.
The invention will now be described below on the basis of a few
exemplary embodiments. The amounts indicated are understood to be %
by weight, unless otherwise indicated.
All the embodiments disclosed herein in conjunction with the binder
system can of course also be used with the applications and methods
described herein and vice versa.
EXAMPLES
Raw Materials:
PPG2000: Voranol 2000 L, propylene glycol, Mw=2000 g/mol, Dow
Lupranat MIS: diphenylmethane diisocyanate, isomer mixture,
BASF
Glycerin carbonate: Jeffsol glycerin carbonate
(4-hydroxymethyl-1,3-dioxolan-2-one), Huntsman
TIB Kat 216: dioctyltin dilaurate, TIB Chemicals
Epoxy 1: commercially available difunctional propylene glycol-based
epoxy resin (EEW 320 g/mol)
Amine 1: commercially available difunctional amine with only
primary amino groups, Mw=176 g/mol
Amine 2: commercially available hyperbranched polyethyleneimine
(primary/secondary/tertiary amine ratio: 1/0.9/0.5), Mw=800
g/mol
Preparation of the Components:
Synthesis of the Solvent-free Prepolymer 1 (KA1)
PPG2000 (435.46 g) is placed in a three-neck flask, dehydrated (10
mbar, 80.degree. C.) for 1 hour and aerated with nitrogen. After
cooling and storing overnight under a protective gas, Lupranat MIS
(104.69 g) was added, and after dissolving completely, the reaction
mixture was adjusted to 80.degree. C. again. NCO titrations are
performed regularly and at NCO=2.91%, glycerin carbonate (46.30 g)
is added at a lower temperature (50.6.degree. C.). Immediately
following that, 0.05% by weight TIB Kat 216 (0.30 g) was
additionally added and after the exothermic reaction was finished,
the reaction mixture was again heated to 80.degree. C. until
reaching NCO <0.1%.
Synthesis of the Solvent-Based Prepolymer 2 (KA2)
PPG2000 (1548.14 g) is placed in a three-neck flask, dehydrated
(<10 mbar, 80.degree. C.) for 1 hour and aerated with nitrogen.
After cooling and storing overnight under a protective gas, the
reaction mixture was adjusted immediately to approx. 34.degree. C.
and Lupranat MIS (371.92 g) was added. After complete
homogenization, the reaction mixture is again set or 80.degree. C.
NCO titrations are carried out regularly and at NCO=3.01%, glycerin
carbonate (164.69 g) is added at a lower temperature (50.2.degree.
C.). Immediately after that, 0.05% by weight TIB Kat 216 (0.30 g)
was additionally added, and after the exothermic reaction was
completed, the reaction mixture was again heated to 80.degree. C.
until reaching NCO<0.1%. Next at approx. 55.degree. C., ethanol
(1390.46 g) was added to achieve a solids content 60% by
weight.
Component A with Epoxy (KA3)
KA1 (2100 g) was placed in a vessel and epoxy resin was added to
epoxy 1 (176 g). The mixture was stirred with a wooden spatula
until it was homogenized and was stored until use.
Preparation of the Curing Agent (KB1)
Amine 1 (20.00 g) and amine 2 (80.09 g) were mixed at one
temperature using a magnetic stirrer until the mixture was
homogenous.
Preparing the adhesives and laminations:
Preparation of the Solvent-Based Adhesive 1 and Lamination (KS1)
(Comparative Example)
KA1 (11.00 g) was dissolved in ethyl acetate (35.4805 g). In
addition KB1 (0.8268 g) was added (ratio of primary
amine/cyclocarbonate=1/1-equivalent). This produces an adhesive
that has a solids content of 25% by weight and can be laminated
(KS1). KS1 was applied to a PET film using a spiral doctor
applicator (0.08 mm), and the solvent was evaporated for 5 minutes
at 90.degree. C. in a drying cabinet. Immediately thereafter the
lamination was completed with a PE film (surface corona pretreated)
with the help of a laboratory lamination device. The laminate (2 to
3.5 g/m.sup.2, dry) was stored at 40.degree. C. under pressure (5
kg weight) and strips were cut off regularly to determine the
laminate adhesion (15 mm wide strips, 90.degree. peel tests on a
tensile testing machine at 100 mm/min). An IR spectrum was recorded
of the PE layer of laminate (ATR). Laminate adhesion after one day
at 40.degree. C.: PET/PE 0.72 N/15 mm, co-adhesive break, both
strips still tacky. The IR spectrum after 3 days at 40.degree. C.
still had the cyclocarbonate carbonyl group band at 1818.30
cm.sup.-1.
Preparing the Solvent-Based Adhesive 2 and Lamination (KS2)
(According to the Invention)
KA3 (2276 g) was dissolved in ethanol (2330 g) and the curing agent
KB1 (157 g) was added to it (ratio of primary
amine/cyclocarbonate=1/1-equivalent) and homogenized using wooden
spatula. The result was an adhesive containing 32% by weight solids
which could be laminated (KS2). KS2 was applied by means of a
laboratory combination lamination system with roller application
(engraving roller with 50 lines per cm) and the parameters were
adjusted so that the application weight (dry) was approx. 2.5
g/m.sup.2. The laminated wound roll was stored at 40.degree. C.
immediately after lamination. Laminate adhesion after 1 day at
40.degree. C.: PET/PE: 2.05 N/15 mm, adhesive break, PE still
tacky. IR spectrum after 2 days at 40.degree. C. no longer had a
band for the cyclocarbonate carbonyl group at 1818.30
cm.sup.-1.
* * * * *